Orleanesia pleurostachys (Linden & Rchb.f.) Garay & Dunsterville (1965: 228)

Gonçalves, Gabriel F., Mauad, Anna Victoria S. R., Taques, Giuliana, Smidt, Eric C. & Barros, Fábio De, 2019, Molecular and morphological phylogenetic analysis and taxonomic revision of the genus Orleanesia (Laeliinae, Epidendroideae, Orchidaceae), Phytotaxa 392 (1), pp. 1-18 : 13

5. Orleanesia pleurostachys (Linden & Rchb.f.) Garay & Dunsterville (1965: 228) ≡ Ponera pleurostachys Linden

& Rchb.f. (1854: 282) ≡ Huebneria pleurostachys (Linden & Rchb.f.) Brieger (1976: 29–32) ≡ Pseudorleanesia pleurostachys (Linden & Rchb.f.) Rauschert (1983: 466) . Type:— COLOMBIA. Norte de Santander: Teorama, June

1846–1852, L. Schlim & L.J. Voyage 1190 (holotype W, [Digital Image!]).

= Orleanesia ecuadorana Dodson (1997: 277) . Type:— ECUADOR. Pastaza: along road Puerto Napo to Puyo, 800 m, 29 December 1983, Thurston s.n. (holotype SEL).

= Orleanesia pradei Schweinfurth & Garay (1953: 182) . Type:— VENEZUELA. Falcon, November 1950, N.H. Prade s.n. (holotype AMES 575, [Digital Image]).

Epiphyte; pseudobulbs fusiform, stipitate, 4–44 cm long. Leaves oblong to oblanceolate, 5–13 × 0.4–1.2 cm, fleshy, present only in the upper portion of the pseudobulb. Inflorescence in panicle, 17–56 cm long, lateral branches 2.5–10.5 cm long, flowers along the entire branches with imbricate sheaths at the base. Flowers yellow, rarely purple; dorsal sepal lanceolate, 1.1–1.2 × 0.3 cm, apex acute, base sessile; lateral sepals lanceolate, 0.8–1.1 × 0.3–0.5 cm, falcate, apex cuspidate, base sessile; petals spathulate, erect, 0.8–1.2 × 0.2–0.3 cm, apex acuminate, base attenuate; lip obovate, 0.6–1 × 0.4–0.5 cm, apex obtuse, base attenuate. Gynostemium 0.7–1 cm long. Anther globose; pollinia 4, in pairs of the same size. Ovary + pedicel 1–1.5 cm long. Fruits fusiform, glabrous.

Phenology: —Flowers April to August, but due to its successive flowers, this period can be extended until later months.

Distribution and habitat: —Amazon forest, dry semi-deciduous forests (Llanos). Colombia, Ecuador and Venezuela. ( Fig. 3 ).

Nomenclature notes: — Orleanesia ecuadorana was previously cited exclusively for Ecuador, with, the holotype and the paratype being the only known vouchers; however, the current location of these materials is unknown. When describing the species, Dodson (1997) designated the herbarium SEL as the location where the types were housed. The curator of SEL reported that there was an entry of these purported types in the herbarium register, but no material related to the species could be found. Despite the absence of its holotype and paratype, the description and illustration of the species given by Dodson (1997) make it clear its similarity to O. pleurostachys . Both taxa have paniculate inflorescences with long lateral branches covered by imbricated bracts with flowers coming out from the base of the branches, which is a unique characteristic of the genus. Their flowers are also very similar, and no diagnostic characters could be found to justify their segregation into two different species. Furthermore, both species occur in Ecuador and no subsequent registered voucher material could be found for O. ecuadorana beyond the types. Therefore, we propose that O. ecuadorana be treated as a synonym under O. pleurostachys .

Taxonomic notes: —This species can be identified by its spathulate erect petals, globose anther, and paniculate inflorescences with long lateral branches. The lateral branches are covered with imbricate sheaths with many successive flowers originating at its base and extending toward its terminus.

Conservation status: —Although the species occurs throughout several South American countries, there are few records in herbaria and it is mentioned in only few floristic studies. The species suffers from habitat loss due to the advancement of urbanization and deforestation. Due to its EOO (162,712,050 km ²) and AOO (24,000 km ²), we classify the species as Least Concern (LC).

Specimens examined: — COLOMBIA. Norte de Santander: Teorama , 1846, Schlim & Voyage 1190 ( W [Digital Image]) . VENEZUELA. Falcón: s.loc., September 1950, Prade s.n. ( AMES 575 [Digital Image]) ; Merida: s.loc., 02 June 1949, Renz 5468.1 ( RENZ [Digital Image]) ; idem: s.loc., 02 June 1949, Renz 5468.2 ( RENZ [Digital Image]) ; Tachira: s.loc., 02 November 1953, Renz 8061 ( RENZ [Digital Image]) ; Zulia: s.loc., December 1950, Renz 6596 ( RENZ [Digital Image]) .

Figures

FIGURE 3. Map of the geographic distribution of Orleanesia based upon herbarium specimens. Symbols accompanied by asterisk (*) indicate information extracted from previous publications.